Method for reestablishing connection using a RAR in a wireless communication network

1. A method for reestablishing a connection, applied to a terminal, comprising:

sending by the terminal, on a first uplink carrier, a random access request to a network device when the terminal is out of uplink synchronization on the first uplink carrier in a first uplink frequency range supported by the terminal, wherein the first uplink carrier is a carrier that is determined by the network device in the first uplink frequency range in a paired combination of frequency bands supported by both the terminal and the network device, and the paired combination of the frequency bands consists of a first frequency band that comprises the first uplink frequency range and a first downlink frequency range and a supplementary uplink frequency band that comprises at least one second uplink frequency range, the first uplink frequency range being different from the at least one second uplink frequency range;

obtaining, when the random access request on the first uplink carrier fails, a first quantity of failures of the random access request; and

determining a first target uplink frequency range in the at least one second uplink frequency range in the paired combination of the frequency bands when the first quantity of failures reaches a preset threshold value, and sending, on a second uplink carrier in the first target uplink frequency range, the random access request to the network device.

2. The method according to claim 1 , wherein the obtaining a first quantity of failures of the random access request comprises:

adding a count value of a first counter corresponding to the first uplink carrier by one, obtaining the count value of the first counter to obtain the first quantity of failures, wherein the count value of the first counter is added by one when the random access request on the first uplink carrier fails, and is cleared when the random access request is successfully sent.

3. The method according to claim 2 , wherein after the random access request is sent, on the second uplink carrier supported by the terminal, to the network device, the method further comprises:

continuing to determine whether the random access request on the second uplink carrier is successful; obtaining, when the random access request on the second uplink carrier fails, a second quantity of failures of the random access request; determining, when the second quantity of failures reaches the preset threshold value, whether a new uplink frequency range exists in the second uplink frequency range in the paired combination of the frequency bands; and

determining a second target uplink frequency range in the new uplink frequency range when the new uplink frequency range is determined to exist, and sending, on an uplink carrier within the second target uplink frequency range, the random access request to the network device.

4. The method according to claim 1 , wherein the determining a first target uplink frequency range in the second uplink frequency range in the paired combination of the frequency bands comprises:

determining a third uplink frequency range in the second uplink frequency range in the paired combination of the frequency bands, wherein the third uplink frequency range is a frequency range in the second uplink frequency range in which a carrier is less than the first uplink carrier; and

determining an uplink frequency range that corresponds to a carrier having a smallest load in the third uplink frequency range, and determining the uplink frequency range that corresponds to the carrier having the smallest load as the first target uplink frequency range, or, randomly determining an uplink frequency range corresponding to a carrier in the third uplink frequency range as the first target uplink frequency range.

5. The method according to claim 4 , wherein after the random access request is sent, on the second uplink carrier supported by the terminal, to the network device, the method further comprises:

continuing to determine whether the random access request on the second uplink carrier is successful; obtaining, when the random access request on the second uplink carrier fails, a second quantity of failures of the random access request; determining, when the second quantity of failures reaches the preset threshold value, whether a new uplink frequency range exists in the second uplink frequency range in the paired combination of the frequency bands; and

determining a second target uplink frequency range in the new uplink frequency range when the new uplink frequency range is determined to exist, and sending, on an uplink carrier within the second target uplink frequency range, the random access request to the network device.

6. The method according to claim 1 , wherein after the random access request is sent, on the second uplink carrier supported by the terminal, to the network device, the method further comprises:

continuing to determine whether the random access request on the second uplink carrier is successful; obtaining, when the random access request on the second uplink carrier fails, a second quantity of failures of the random access request; determining, when the second quantity of failures reaches the preset threshold value, whether a new uplink frequency range exists in the second uplink frequency range in the paired combination of the frequency bands; and

determining a second target uplink frequency range in the new uplink frequency range when the new uplink frequency range is determined to exist, and sending, on an uplink carrier within the second target uplink frequency range, the random access request to the network device.

7. The method according to claim 6 , wherein the method further comprises:

determining that a wireless link connection fails when the new uplink frequency range is determined not to exist.

8. The method according to claim 6 , wherein the method further comprises:

sending uplink data on the second uplink carrier when the random access request on the second uplink carrier is successful.

9. A non-transitory computer-readable storage medium, comprising one or more programs, wherein the one or more programs are configured to perform a method for reestablishing a connection applied to a terminal;

wherein the method comprises:

sending by the terminal, on a first uplink carrier, a random access request to a network device when the terminal is out of uplink synchronization on the first uplink carrier in a first uplink frequency range supported by the terminal, wherein the first uplink carrier is a carrier that is determined by the network device in the first uplink frequency range in a paired combination of frequency bands supported by both the terminal and the network device, and the paired combination of the frequency bands consists of a first frequency band that comprises the first uplink frequency range and a first downlink frequency range and a supplementary uplink frequency band that comprises at least one second uplink frequency range, the first uplink frequency range being different from the at least one second uplink frequency range;

obtaining, when the random access request on the first uplink carrier fails, a first quantity of failures of the random access request; and

determining a first target uplink frequency range in the at least one second uplink frequency range in the paired combination of the frequency bands when the first quantity of failures reaches a preset threshold value, and sending, on a second uplink carrier in the first target uplink frequency range, the random access request to the network device.

10. The non-transitory computer-readable storage medium according to claim 9 , wherein the obtaining a first quantity of failures of the random access request comprises:

adding a count value of a first counter corresponding to the first uplink carrier by one, obtaining the count value of the first counter to obtain the first quantity of failures, wherein the count value of the first counter is added by one when the random access request on the first uplink carrier fails, and is cleared when the random access request is successfully sent.

11. The non-transitory computer-readable storage medium according to claim 9 , wherein the determining a first target uplink frequency range in the second uplink frequency range in the paired combination of the frequency bands comprises:

determining a third uplink frequency range in the second uplink frequency range in the paired combination of the frequency bands, wherein the third uplink frequency range is a frequency range in the second uplink frequency range in which a carrier is less than the first uplink carrier; and

determining an uplink frequency range that corresponds to a carrier having a smallest load in the third uplink frequency range, and determining the uplink frequency range that corresponds to the carrier having the smallest load as the first target uplink frequency range, or, randomly determining an uplink frequency range corresponding to a carrier in the third uplink frequency range as the first target uplink frequency range.

12. The non-transitory computer-readable storage medium according to claim 9 , wherein after the random access request is sent, on the second uplink carrier supported by the terminal, to the network device, the method further comprises:

continuing to determine whether the random access request on the second uplink carrier is successful; obtaining, when the random access request on the second uplink carrier fails, a second quantity of failures of the random access request; determining, when the second quantity of failures reaches the preset threshold value, whether a new uplink frequency range exists in the second uplink frequency range in the paired combination of the frequency bands; and

determining a second target uplink frequency range in the new uplink frequency range when the new uplink frequency range is determined to exist, and sending, on an uplink carrier within the second target uplink frequency range, the random access request to the network device.

13. The non-transitory computer-readable storage medium according to claim 12 , wherein the method further comprises:

determining that a wireless link connection fails when the new uplink frequency range is determined not to exist.

14. The non-transitory computer-readable storage medium according to claim 12 , wherein the method further comprises:

sending uplink data on the second uplink carrier when the random access request on the second uplink carrier is successful.

15. A terminal, comprising:

a non-transitory computer-readable storage medium and one or more processors;

wherein the non-transitory computer-readable storage medium comprises one or more programs, and the one or more processors are configured to execute the one or more programs in the non-transitory computer-readable storage medium;

wherein the one or more programs are configured to perform a method for reestablishing a connection applied to a terminal;

wherein the method comprises:

sending by the terminal, on a first uplink carrier, a random access request to a network device when the terminal is out of uplink synchronization on the first uplink carrier in a first uplink frequency range supported by the terminal, wherein the first uplink carrier is a carrier that is determined by the network device in the first uplink frequency range in a paired combination of frequency bands supported by both the terminal and the network device, and the paired combination of the frequency bands consists of a first frequency band that comprises the first uplink frequency range and a first downlink frequency range and a supplementary uplink frequency band that comprises at least one second uplink frequency range, the first uplink frequency range being different from the at least one second uplink frequency range;

obtaining, when the random access request on the first uplink carrier fails, a first quantity of failures of the random access request; and

determining a first target uplink frequency range in the at least one second uplink frequency range in the paired combination of the frequency bands when the first quantity of failures reaches a preset threshold value, and sending, on a second uplink carrier in the first target uplink frequency range, the random access request to the network device.

16. The terminal according to claim 15 , wherein the obtaining a first quantity of failures of the random access request comprises:

adding a count value of a first counter corresponding to the first uplink carrier by one, obtaining the count value of the first counter to obtain the first quantity of failures, wherein the count value of the first counter is added by one when the random access request on the first uplink carrier fails, and is cleared when the random access request is successfully sent.

17. The terminal according to claim 15 , wherein the determining a first target uplink frequency range in the second uplink frequency range in the paired combination of the frequency bands comprises:

determining a third uplink frequency range in the second uplink frequency range in the paired combination of the frequency bands, wherein the third uplink frequency range is a frequency range in the second uplink frequency range in which a carrier is less than the first uplink carrier; and

determining an uplink frequency range that corresponds to a carrier having a smallest load in the third uplink frequency range, and determining the uplink frequency range that corresponds to the carrier having the smallest load as the first target uplink frequency range, or, randomly determining an uplink frequency range corresponding to a carrier in the third uplink frequency range as the first target uplink frequency range.

18. The terminal according to claim 15 , wherein after the random access request is sent, on the second uplink carrier supported by the terminal, to the network device, the method further comprises:

continuing to determine whether the random access request on the second uplink carrier is successful; obtaining, when the random access request on the second uplink carrier fails, a second quantity of failures of the random access request; determining, when the second quantity of failures reaches the preset threshold value, whether a new uplink frequency range exists in the second uplink frequency range in the paired combination of the frequency bands; and

determining a second target uplink frequency range in the new uplink frequency range when the new uplink frequency range is determined to exist, and sending, on an uplink carrier within the second target uplink frequency range, the random access request to the network device.

19. The terminal according to claim 18 , wherein the method further comprises:

determining that a wireless link connection fails when the new uplink frequency range is determined not to exist.

20. The terminal according to claim 18 , wherein the method further comprises:

sending uplink data on the second uplink carrier when the random access request on the second uplink carrier is successful.